Dear Yong Peng,

> please advise on the word: aruupasa~n~nii

This is about arupa jhanas throuh kasina practice.

See the translation of Thanissaro Bhikkhu:

(iii) "One percipient of the formless internally sees forms externally
as limited, beautiful & ugly. Mastering them, he is percipient of 'I
know; I see.' This is the third dimension of [mental] mastery.

(iv) "One percipient of the formless internally sees forms externally as
immeasurable, beautiful & ugly. Mastering them, he is percipient of 'I
know; I see.' This is the fourth dimension of [mental] mastery.

http://www.accesstoinsight.org/canon/sutta/anguttara/an10-029.html

Metta, Dmytro